Blab is a live steaming tool that enables you to join up to four-person video conversations. As a participant in a “Blab” you can request to join any chat that’s going on and switch place with one of the four participants taking part in the chat, if the moderator allows. As a moderator and organizer of the “Blab-event” you have the ability to mute any or all of the four video chatters. So for example if three people are interviewing someone, you can choose to mute the three interviewers and just listen to the answers from the interview subject. All Blabs can be recorded to watch later, which is one of its big strengths.
Try it out: https://blab.im/